1. Field
An aspect of an embodiment of the present invention relates to a display device, and more particularly, to an organic light emitting display device.
2. Description of the Related Art
Recently, various flat panel display devices, which are lighter and have smaller volume compared to a cathode ray tube, have been developed.
Particularly, an organic light emitting display device among the flat panel display devices display an image by using (utilizing) an organic light emitting diode, which is a self-light emitting device, thereby exhibiting excellent luminance and color purity and thus attracting attention as a next generation display device.
The organic light emitting display device is divided into a Passive Matrix Organic Light Emitting Diode (PMOLED) and an Active Matrix Organic Light Emitting Diode (AMOLED).
The AMOLED includes a plurality of pixels positioned at cross portions (regions) of scan lines and data lines. Further, each pixel includes an organic light emitting diode and a pixel circuit for driving the organic light emitting diode. The pixel circuit is typically formed of a switching transistor, a driving transistor, and a storage capacitor.
The AMOLED has an advantage of low power consumption, thereby usefully used in a portable display device and the like.
However, in the case of the AMOLED, a small leakage current may be generated in the driving transistor while implementing a black image due to a device characteristic of the driving transistor included in the pixel circuit, and luminance to implement the black image (black luminance) is increased by the leakage current, so that the black image fails to display complete black.
This causes deterioration of a contract ratio quality of the organic light emitting display device.